This invention relates to wheel balancing equipment, and, in particular, to a caliper for use with wheel balancers.
Electronic wheel assembly balancers are known. Such balancers are used to determine the magnitude and radial location for weights to correct for imbalance which may exist in a wheel assembly. To determine the appropriate corrective weight to be applied, the diameter of the plane in which the corrective weight is to be placed must be supplied to the balancer. If the wheel assembly is to be dynamically balanced, the balancer must also be supplied with the distance between the planes in which corrective weights are to be placed. If the electronic balancer has an electronic data entry means, these dimensions can be automatically supplied to the balancer. However, if the balancer does not have such data entry means, the dimensions must be manually measured and entered. The dimensions can be entered using knobs, such as disclosed in co-assigned Pat. No. 5,156,049, which is incorporated herein by reference.
To manually enter the dimensions, the dimensions must of course first be determined. The diameter of the weight plane is presently often determined using a tape measure or the like. Although a balancer operator may be able to properly read the tape measure, he may inadvertently take the measurement slightly off of the diameter. He will thus supply a measurement smaller than the actual diameter of the wheel assembly. The balancer will determine the corrective weight at this wrong diameter and an incorrect weight, therefore, will be applied to the wheel. In a dynamic balancing operation, the operator must also supply the balancer with the wheel width. The wheel width at the rim is usually relied upon as the distance between the weight planes. However, if the weights are not being placed on the rim where the operator knows the distance between the planes, the distance between the planes (i.e., the wheel width) must be manually measured. This distance, like the wheel diameter, can inadvertantly be measured incorrectly. A wrong dimension will be supplied to the balancer and an incorrect weight will be applied to the wheel.